VXL is a 2-pole motor, Neu's, 1/8 Castle Creation motors, Medusa's and several other use 4-poles.
I've ran a 4-pole motor (medusa) off an older Non-Waterproof Vxl before just fine(I have video), But my Waterproof VXL didn't do very well with a 4-pole.
I think they added a rev limit or something as it would take off great then start to shutter at higher rpms.
Having twice the amount of poles to count the VXL-3 hits a 2-pole rev limit half as fast.
For two pole motors try here.
http://www.offshoreelectrics.com/pro...ushless+Motors
Look at the 9L to 6L size and speed of 2-pole motors.